Endocrinology
Albumin-Corrected Calcium Calculator (Payne Formula)
Calculates corrected total serum calcium (mg/dL & mmol/L) for hypoalbuminemia and stratifies hypercalcemic crisis risk.
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Parameters
Albumin-Corrected Calcium Calculator (Payne Formula) Result
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Formula
Corrected Calcium (mg/dL) = Measured Calcium (mg/dL) + 0.8 × [4.0 - Serum Albumin (g/dL)]
Corrected Calcium (mmol/L) = Measured Calcium (mmol/L) + 0.02 × [40 - Serum Albumin (g/L)]Clinical Pearls
Avoids erroneous intravenous calcium administration in asymptomatic pseudohypocalcemia and unmasks occult hypercalcemia in malnourished or oncologic patients.
Limitations
The Payne equation can be inaccurate in end-stage renal disease, severe acidemia, or alkalemia; order ionized calcium for definitive decision-making.